In March, we discussed a new Teflon lawsuit filed by the Ohio attorney general against DuPont Co. and its spin-off, Chemours Co. The lawsuit alleged that DuPont had been dumping dangerous chemicals into the Ohio River, knowingly exposing downstream residents and the environment to serious risks of harm.
The chemical in question is known as perfluorooctanoic acid (PFOA) or C8 (after its chemical formula, C8HF15O2). PFOA was originally manufactured by 3M, and it was used by DuPont in the past to manufacture Teflon, the nonstick surface that still coats many homes’ pots and pans.
We were recently reminded of the AG’s lawsuit when we saw reporting on information disclosed in similar litigation between the Minnesota attorney general and 3M. According to The Intercept, internal 3M documents released as a result of that lawsuit show that the company knew of the dangers posed by PFOA beginning in the 1970s and took actions to hide that information from government regulators and the public.
With PFOA back in the news again, we thought it would be helpful to take a closer look at precisely what makes PFOA so dangerous to humans and the environment.
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- PFOA is a toxic, carcinogenic manmade chemical that lasts indefinitely in the environment and can be transported by natural forces throughout the world.
- PFOA accumulates in the human body from repeat exposure, poisoning the blood, liver, and kidney for years even after exposure ceases.
- Big companies like 3M and DuPont knowingly released PFOA into the environment, contaminating groundwater, animals, and people for thousands of miles.
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What makes PFOA so dangerous?
To understand the risks posed by PFOA, we need look no further than a March 2014 “emerging contaminant” fact sheet published by the Environmental Protection Agency (EPA). The EPA’s fact sheet, which covers PFOA and a similar chemical called perfluorooctane sulfonate (PFOS) summarizes the current scientific understanding of the two chemicals.
According to the EPA, the “toxicity, mobility, and bioaccumulation potential of PFOS and PFOA pose potential adverse effects for the environment and human health.”
Toxicity
The full extent of the dangers posed by PFOA to people is not yet known. The EPA reports that in mice, PFOA has “raised concerns about potential developmental, reproductive and other systemic effects,” including an “adverse effect on mammary gland development.” Plus, PFOA has been linked to the development of tumors in mice livers.
Although studies involving mice can be suggestive of a chemical’s effect in humans, they are not conclusive.
But studies have also been conducted on people. In one, scientists determined that employees at plants that manufacture or use PFOA had elevated mortality rates for kidney cancer and an increase in mortality for male workers with diabetes. Another suggested that PFOA is associated with thyroid disease in people, and others have shown damage to DNA in the human liver. DNA damage is one well-known cause of cancer.
As the Ohio attorney general summarized the existing research in his press release announcing his February lawsuit, “[e]xposure to PFOA has been linked to health problems in humans, including kidney and testicular cancer, thyroid disease, low birth weight, and high cholesterol.”
Although some question the link between PFOA and these health problems, the evidence for the toxicity of the chemical led a panel of scientific advisers to the EPA to classify it as “likely to be carcinogenic to humans.”
Mobility
As we mentioned in our March article, PFOA has been found hundreds of miles from its original source, such as a factory manufacturing it or a landfill or other dumping site. In fact, according to the EPA, PFOA has been discovered even further away than that, including in the livers of Canadian Arctic polar bears and in “remote regions of the Arctic caps.”
Those findings are remarkable, because PFOA is a manmade chemical that does not occur naturally. Wherever it is found in the environment, it can be traced to human action. (Some natural factors, such as bacteria or environmental degradation, can produce PFOA, but only from other manmade chemicals, such as the chemicals used to make PFOA.)
How could PFOA travel so far? The fact sheet points to several potential pathways by which the chemical could spread:
- Travel through the air. PFOA or precursor chemicals can be carried through the air for very long distances.
- Travel via ocean currents. PFOA that makes its way into the ocean could be distributed via ocean currents or marine aerosols.
- Consumption of contaminated food sources. PFOA contamination can be passed up the food chain when an animal (or person) eats a food that has been exposed to the chemical. For example, according to the EPA, “fish and fishery products seem to be one of the primary sources of human exposure to PFOS.”
Because PFOA is highly persistent—it does not degrade as a result of natural forces—the chemical can survive indefinitely even after being transported in one of these ways around the world.
Bioaccumulation
PFOA’s persistence doesn’t just pose risks to the environment. It also means that the chemical can remain in people’s bodies for an extended period. As a result, there is a risk of bioaccumulation from continuous or repeated exposure to the chemical. “Bioaccumulation” means that the chemical will build up inside the body, making adverse effects more likely.
In the body, PFOA accumulates in blood, the kidney, and the liver. And it stays there for years: According to the EPA, the half-life of PFOA in humans—that is, the time it takes for the body to eliminate one-half of the original amount—is somewhere between two and four years.
That means that even after a person’s exposure to PFOA has ended, he or she will continue to carry the chemical in his or her body for many years, where it continues to poison the body. Any subsequent exposure during that time will only add to the contamination.
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